[I]n order to elaborate the Dharma of Sentient Beings, Chih-i brings forth the concept of the Ten Dharma-realms (hell-dwellers, hungry ghosts, animals, asuras, humans, heavenly beings, śrāvakas, pratyekabuddhas, bodhisattvas, and Buddhas), as sentient beings are what constitute the Ten Dharma-realms. The first nine realms are said by Chih-i to belong to the Relative Truth, and the Buddha-realm to the Ultimate Truth. Each of the ten realms is characterized by the Ten Suchnesses (appearance, nature, substance, power, function, causes, conditions, effects, retributions, and beginning and end ultimately-alike). Whereas the Ten Suchnesses are regarded by Chih-i as the general characteristics of the Ten Dharma-realms, the Ten Suchnesses are viewed as the Ultimate Truth of all dharmas. Hence, the Ten Suchnesses are the characteristics of the Ultimate Truth. Seeing that the Ultimate Truth is possessed by the Ten Dharma-realms that consist of the Relative and Ultimate, this Ultimate Truth embraces both the Relative and the Ultimate. Chih-i’s interpretation of the Dharma of Sentient Beings aims at associating it with the Dharma of Buddha, for the latter concerns the Buddha’s knowledge of the Relative and the Ultimate, with which the Buddha is able to conceive the Ultimate Truth that embraces the whole Dharma-realm. The Dharma of Mind, on the other hand, as Chih-i’s category of approaching the Ultimate Truth of Buddhahood includes the former two types of the Dharma. This is to say that the Ten Dharmarealms that are characterized by the Ten Suchnesses as the Ultimate Truth of dharmas are contained in one’s mind. One’s mind that embraces the whole universe is based on Chih-i’s view that the Buddha-nature is possessed by all sentient beings. Since the Buddha-nature is inherent in all beings, contemplating one’s mind is the ultimate approach to attain Buddhahood. To Chih-i, if the Buddha-nature is considered to be the invisible state of Buddhahood, the realization of Buddhahood is only the matter of manifesting this Buddha-nature, i.e., one’s enlightenment is the visible state of Buddhahood. Therefore, the Dharma of Mind introduces the practical approach in terms of mind contemplation, through which Buddhahood can be realized. (Vol.2, Page 70)